surreptitious /sur-əp-tishˈəs/

1. Done by stealth or fraud
2. Stealthy

• stabiliser
• stabilisers
• stabilises
• stabilising
• stabilities
• stability
• stabilization
• stabilizations
• stabilizator
• stabilizators
• stabilize
• stabilized
• stabilizer
• stabilizers
• stabilizes
• stabilizing
• stab in the back
• stable
• stableboy
• stableboys
• stable companion
• stable companions
• stabled
• stable door
• stable doors